Boys with poor sleep habits have a “very high risk of obesity” according to a study by researchers at the Faculty of Science and Technology of the University of Coimbra (FCTUC), reports The Portugal News.

Based on the recommendations of the American Academy of Pediatrics (2016), which established adequate sleep to be between nine and 12 hours a night for children aged 6 to 12, the research aimed to analyze “the relationship between irregular sleeping habits,” (more or less time than recommended) and “the risk of obesity in the Portuguese pediatric population.”

The researchers studied the sleep habits of 8,273 children (4,183 females) between the ages of six and nine, as well as “physical activity and sedentary behaviours (e.g. time spent watching television or playing computer games), through questionnaires completed by the parents,” said the University of Coimbra (UC), in a statement sent to Lusa News Agency on Monday. The relationship between sleep habits and the risk of obesity for boys and girls were calculated separately.